Athletes will be able to transform their hydration with Nix’s new Hydration Biosensor sweat patch. Having just launched on to the consumer market, the product was named as an Innovation Award Honoree at CES 2023 in the Digital Health category and also made Time’s Best Inventions of 2022 list.

Getting hydration right is one of the pillars of an optimal training session or race. Too much intake can result in hyponatremia – where sodium levels in blood are lower than normal, which can cause a fatal reaction, while dehydration can bring on a range of unwanted effects from fatigue and muscle cramping to organ failure.

Sweat rate, altitude and temperature, all complicate the athlete’s hydration situation – and yet many people hydrate based on thirst or weight loss after training.

“Athletes are acutely aware of the importance of proper hydration for performance and safety, but have never had the proper tools until now,” said Meridith Cass, founder and CEO of Nix. “Nix eliminates the traditional trial-and-error approach to hydrating – athletes can now get precise, personalised hydration metrics, telling them exactly when, what and how much to drink.”

The size of a watch face, weighing 14g, the single-use patch (with a 36-hour life) sticks onto the surface of the skin with kinesiology tape to make it both flexible and comfortable. It must be placed in the middle of either the left or right bicep, with the patch facing upwards, to work effectively.

The patch analyses sweat composition every second to provide athletes with personalised real-time hydration data – tracking fluid and electrolyte losses – and provides live notifications. A clip-on pod (rechargable, with 24-hour battery) sends data to the Nix app or Apple and Garmin watches. Over the next few months, Nix is also aiming to partner with Strava, TrainingPeaks, Wahoo and Zwift.

After the workout, a summary is provided to help users improve their hydration strategy. It also offers hydration products by electrolyte composition to help them choose the best option for their personal hydration needs.

Cass, a Harvard Business School graduate and marathoner, founded Nix in 2015. The company says its mission is “self-health” and that “empowering humans to manage their own physical, mental, and behavioral health is the most impactful thing we can do to change the current problems with our healthcare system”.

The company works with a group of specialised sports, science and business advisors, including ultra runner Dean Karnazes, Doug Casa, PhD, CEO of the Korey Stringer Institute for hydration and head illness, and Tom Fowler, the former president of Polar.

The Nix Hydration Biosensor – which comes with one pod, four sweat patches and a charging case – can be purchased via the Nix website for US$129.